This invention relates generally to golf training devices and more specifically to a golf putting training device that allows a golfer to practice putting a golf ball a precise distance in a very small area. In the game of golf, at least half of the strokes allocated to comprising the par for 18 holes are for putting. The putter is the club used most in a round of golf. Putting is the game within the game of golf that greatly affects the golfer's overall score. The most common problem associated with putting in a round of golf is the three-putt. After hitting an iron onto the green in regulation 25 feet from the hole, the golfer strokes the first putt either far short of the hole or far past the hole leaving a par putt of 6 feet or more. Most often, an average golfer will miss putts of more than 6 feet. Therefore, to eliminate three putts, a golfer must stroke the first putt 3 feet or closer from the hole to assure making the next putt. There are two components that comprise putting. They are distance and direction. Professional golf instructors know that in putting, distance is more important than direction. Therefore, average golfers can improve their putting ability by learning to hit long putts a precise distance ensuring that the remaining putt is a short tap-in. Practicing long putts is difficult due to many factors. It is sometimes difficult to find a practice green that is relatively flat for 20 feet or more. If the practice green is busy, it is difficult to find a path to a hole 20 feet or more that does not cross the path of another golfer practicing. Most golfers don't have the time to travel to a golf facility just to practice long putts. When they do go to the golf course for practice, they would rather hit drives and iron shots. A putting distance control training device that can be used indoors at home or in the office requiring only a very small space would allow a golfer to improve first putt distance control and thus improve overall scoring.
A variety of golf putting training devices have been developed to aid golfers in putting a golf ball a desired distance. For example, U.S. Pat. No. 5,788,583 discloses a system which predicts the distance that a golf ball will travel when struck by a putter head during a putting swing. The golfer swings the putter head over two optical sensors located a predetermined distance from each other. A timer generates a time difference value representing a difference between the time when the putter head travels over the first sensor and a second time when the putter head travels over the second sensor. A microprocessor determines the predicted distance by using the time difference measurement and green condition settings set by the golfer to fetch a predicted distance value from a lookup table predefined in memory. The golfer continues taking practice strokes until the predicted distance matches the actual distance to the hole. This approach uses as its basis for golf ball distance estimation, the speed of the putter head during a practice stroke. In order to relate putter head speed to predicted golf ball distance, a lookup table is employed whose values are determined empirically through a data acquisition process. This process is performed by repeatedly placing a golf ball near the sensors, striking the ball with a putting stroke, recording the putter head time difference value, and then measuring and recording the actual distance that the ball rolled on the green. By repeating this process for several more practice strokes, the lookup table contents can be determined for a specific putt on a specific green. U.S. Pat. No. 5,788,583 requires a large amount of empirical data to be entered prior to using the device as a trainer and each data set entered covers one particular distance putt.
U.S. Pat. No. 6,146,283 discloses a system which assists golfers in practicing their respective putting stroke by indicating the distance a practice putt would have traveled upon a simulated green having a selected stimp value. The practice device employs a pair of putting targets mounted to a rotatable putting force sensor at opposite ends so as to counterbalance one another. The putting target is struck by a putter during a practice stroke resulting in the counterbalanced putting targets spinning along the axis of the stroke. The simulated speed of a golf ball is determined by relating the rotations per second of the putting force sensor to linear velocity. The linear velocity has a mass correction factor applied if the inertial mass of the counterbalanced putting targets differ significantly from that of a single golf ball. Finally, a microprocessor calculates the estimated distance based on the measured rotational speed and the stimp green speed selector setting.
U.S. Pat. No. 4,180,270 discloses a putting training apparatus which includes two retractable sensors flanking an imaginary golf ball. By swinging a putter at the imaginary ball, the first and second sensors are actuated and, based on which of the two sensors was actuated first, determines if the putter was open or closed at impact. The time difference in the two sensor actuations determines the direction accuracy of the golfer's putting stroke. A second embodiment of this patent employs a third and fourth sensor that actuate at a fixed distance from the two direction sensors. Using the time measured from the first two sensor actuations to the third and fourth sensor actuations, a distance estimate is made.
U.S. Pat. No. 5,788,583, U.S. Pat. No. 6,146,283, and U.S. Pat. No. 4,180,270 all predict the distance that a golf ball will roll. However, none in their basic mode of operation requires the striking and subsequent roll of a golf ball. Furthermore, none of the cited patents make direct speed measurements of a rolling golf ball during their use as training devices. Empirical data tables and mass correction factors are employed to model the predicted behavior of a golf ball struck by a putter.
U.S. Pat. No. 6,540,620 discloses a golf putter training device which aids a golfer in judging the speed of impact of a golf club head upon a ball. A golf ball is struck by a putter into an elongated structure equipped with a pair of optical sensors that measure the travel time of the golf ball as it passes from the first to the second sensor pair. The resulting count value is presented to a digital to analog converter whose output connects to a digital panel meter for display to the golfer. The number presented to the golfer is not a prediction of the golf ball roll distance but a relative indication of the force of impact so that the golfer can learn to repeat the same force stroke.